Single-cell profile of atrial human fibroblasts in cardiac arrhythmia atrial fibrillation (AF) - 10x
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ABSTRACT: Atrial fibrillation (AF), the most common cardiac arrhythmia, is a major contributor to population mortality and morbidity. The goal of this study is to explore molecular mechanisms of the AF-induced profibrotic remodelling in human atrial fibroblasts (ACFs). Specifically, we assessed single-cell transcriptome of cultured human ACFs treated with calcitonin(CT) or vehicle (from 6 individual patients) and of freshly-isolated ACFs from patients with AF (4 individual patients) vs controls (4 individual patients). We found that ACF transcriptome was unaltered by CT in cultured ACFs, and identified 5 transcriptional clusters with 23 differentially expressed transcripts in AF in freshly-ioslated ACFs.
Project description:Atrial fibrillation (AF), the most common cardiac arrhythmia, is a major contributor to population mortality and morbidity. The goal of this study is to explore molecular mechanisms of the AF-induced profibrotic remodelling in human atrial fibroblasts (ACFs). Specifically, we assessed single-cell transcriptome of cultured human ACFs treated with calcitonin(CT) or vehicle (from 6 individual patients) and of freshly-isolated ACFs from patients with AF (4 individual patients) vs controls (4 individual patients) (SR). We found that ACF transcriptome was unaltered by CT in cultured ACFs, and identified 5 transcriptional clusters with 23 differentially expressed transcripts in AF in freshly-ioslated ACFs.
Project description:Our study aims to illustrate the potential use of atrial iPSC-CMs for modeling AF in a dish, elucidating the underlying cellular mechanisms, and identifying novel mechanism-based therapies custom-tailored for individual patients
Project description:Atrial fibrillation (AF), the most common arrhythmia, is occasionally associated with cardiac developmental defects, but causal relationships are poorly defined. Importantly, functional compensation for developmental defects may mask increased risk of arrhythmia in adults. Here, we deleted 9 amino acids (Δ9) within a highly conserved A-band region of titin, a giant protein that serves as a molecular spring in cardiomyocytes, in both zebrafish and human induced pluripotent stem cell-derived atrial cardiomyocytes (hiPSC-aCMs). We find that the cardiac morphology of ttnaΔ9/Δ9 homozygous zebrafish embryos is perturbed and accompanied by reduced functional output, but ventricular function recovers within a few days of embryonic development, with most embryos reaching adulthood. Despite normal ventricular function, ttnaΔ9/Δ9 adults exhibit AF and atrial cardiomyopathy, with a striking absence of fibrosis, and these findings are recapitulated in TTNΔ9/Δ9-hiPSC-aCMs. Electrophysiological and proteomics analyses reveal atrial action potential shortening and increased expression and function of the cardiac potassium channel Kv7.1 and the slow delayed rectifier potassium current (IKs). Pharmacological suppression of IKs in both models prevents AF and improves atrial contractility. Collectively, these findings reveal how a small internal deletion in a large structural protein causes developmental abnormalities that functionally recover but increase the risk of adult cardiac disease via ion channel remodeling. The observed rescue with targeted antiarrhythmic therapy may have broader implications for the treatment of patients who harbor disease-causing rare variants in sarcomeric proteins.
Project description:Background Atrial fibrosis plays a critical role in the development of atrial fibrillation (AF). Exosome is a promising cell-free therapeutic approach for the treatment of AF. The purpose of this study was to explore the mechanisms underlying exosomes derived from atrial myocytes regulated atrial remodeling and ask whether their manipulation allows for therapeutic modulation of fibrosis potential abnormalities during AF. Methods We isolated exosomes from atrial myocytes and patients serum, microRNA (miRNA) sequencing analyzed the exosomal miRNAs in atrial myocytes-exosomes and patients serum-exosomes. mRNA sequencing and bioinformatics analysis corroborate the key gene as direct targets of miR-210-3p. Results The miRNAs sequencing analysis identified that miR-210-3p expression significantly increased in exosomes of tachypacing atrial myocytes and serum of AF patients. In vitro, the analysis showed that miR-210-3p inhibitor reversed tachypacing-induced proliferation and collagen synthesis in atrial fibroblasts. Accordingly, KO miR-210-3p could reduce the incidence of AF and ameliorate atrial fibrosis induced by Ang Ⅱ. The mRNA sequencing analysis and Dual-Luciferase reporter assay proved that glycerol-3-phosphate dehydrogenase 1-like (GPD1L) is the potential target gene of miR-210-3p. The functional analysis suggests that GPD1L regulated atrial fibrosis via PI3K/AKT signaling pathway. Besides, silencing GPD1L in atrial fibroblasts induced cells proliferation and these effects could be reversed by PI3K inhibitor (LY294002). Conclusion We demonstrate that atrial myocytes-derived exosomal miR-210-3p promoted the proliferation and collagen synthesis via inhibiting GPD1L in atrial fibroblasts. Preventing pathological crosstalk between atrial myocytes and fibroblasts may be as a novel target to improve atrial fibrosis in AF.
Project description:Background: Genomic and experimental studies suggest a role for PITX2 in atrial fibrillation (AF). To assess whether this association is relevant for recurrent AF in patients, we tested whether left atrial PITX2 affects recurrent AF after AF ablation. Methods: mRNA concentrations of PITX2 and its cardiac isoform, PITX2c, were quantified in left atrial appendages (LAA) from patients undergoing thoracoscopic AF ablation, either in whole LAA tissue (n=83) or in LAA cardiomyocytes (n=52), and combined with clinical parameters to predict AF recurrence. Literature suggests bone morphogenetic protein 10 (BMP10) as a PITX2-repressed, atrial-specific, secreted protein. BMP10 plasma concentrations were combined with eleven cardiovascular biomarkers and clinical parameters to predict recurrent AF after catheter ablation in 359 patients. Results: Reduced cardiomyocyte PITX2 concentrations, but not whole LAA tissue PITX2, were associated with AF recurrence after thoracoscopic AF ablation (16% decreased recurrence per 2-(ΔΔCt) increase in PITX2). RNA sequencing, qPCR and Western blotting confirmed BMP10 as one of most PITX2-repressed atrial genes. Left atrial size (hazard ratio per mm increase, HR [95%CI] 1.055 [1.028, 1.082], non-paroxysmal AF (HR 1.672 [1.206, 2.318]) and elevated BMP10 (HR 1.339 [CI 1.159, 1.546] per quartile increase) were predictive of recurrent AF. BMP10 outperformed eleven other cardiovascular biomarkers in predicting recurrent AF. Conclusions: Reduced left atrial cardiomyocyte PITX2 and elevated plasma concentrations of the PITX2-repressed, secreted, atrial protein BMP10 identify patients at risk of recurrent AF after ablation.
Project description:Atrial Fibrillation (AF), an abnormal heart rhythm characterized by the rapid and irregular beating of the atria, is the most common arrhythmia with heavy global burdens. The present project aimed to characterized the feature of metabolites in feces of AF patients by using LC-MS.
Project description:Atrial fibrillation (AF) is the most common heart arrhythmia disease. The greatest risk of atrial fibrillation is stroke, and stroke caused by valvular heart disease with atrial fibrillation (AF-VHD) is more serious. the development mechanism from VHD to AF-VHD is not yet clear. The research on expression profiles of lncRNA and mRNA is helpful to explore molecular mechanism in patients with valvular heart disease who develop atrial fibrillation.
Project description:Atrial fibrillation (AF) is a progressive arrhythmia for which current therapy is inadequate. During AF, rapid stimulation causes atrial remodeling that promotes further AF. The cellular signals that trigger this process remain poorly understood, however, and elucidation of these factors would likely identify new therapeutic targets. We have previously shown that immortalized mouse atrial (HL-1) myocytes subjected to 24 hr of rapid stimulation in culture undergo remodeling similar to that seen in animal models of atrial tachycardia (AT) and human AF. This preparation is devoid of confounding in vivo variables that can modulate gene expression (e.g., hemodynamics). Therefore, we investigated the transcriptional profile associated with early atrial cell remodeling. RNA was harvested from HL-1 cells cultured for 24 hr in the absence and presence of rapid stimulation and subjected to microarray analysis. Data were normalized using Robust Multichip Analysis (RMA), and genes exhibiting significant differential expression were identified using the Significance Analysis of Microarrays (SAM) method. Using this approach, 919 genes were identified that were significantly altered with rapid stimulation (763 up-regulated and 156 down-regulated). For many individual transcripts, changes typical of AF/AT were observed, with marked up-regulation of genes encoding BNP and ANP precursors, heat shock proteins, and MAP kinases, while novel signaling pathways and molecules were also identified. Both stress and survival response were evident, as well as up-regulation of multiple transcription factors. Genes were also functionally classified based on cellular component, biologic process, and molecular function using the Gene Ontology database to permit direct comparison of our data with other gene sets regulated in human AF and experimental AT. For broad categories of genes grouped by functional classification, there was striking conservation between rapidly stimulated HL-1 cells and AF/AT. Results were confirmed using real-time quantitative RT-PCR on 13 genes selected by physiological relevance in AF/AT and regulation in the microarray analysis (up, down, and nonregulated). Rapidly-stimulated atrial myocytes provide a complementary experimental paradigm to explore the initial cellular signals in AT remodeling to identify novel targets in the treatment of AF. Experiment Overall Design: HL-1 cell expression profile in vitro with and without rapid electric stimulation